Portable vacuum cleaners are known in which a fan mounted in a housing of the vacuum cleaner causes suction of air into an intake in the housing and expulsion of air from an exhaust in the housing. The stream of air travelling from the intake to the exhaust passes through a coarse filter having a filter element of metal or plastics and then through a fine filter having a pleated filter element of paper or other fibrous material.
Prior art vacuum cleaners of this type suffer from the drawback that it is very difficult to remove dirt from the filters, as a result of which the filters eventually become ineffective.
Preferred embodiments of the present invention seek to overcome the above disadvantages of the prior art.